Hammer mill



M y 5, 1 i w. J.,CLEMENT 1,897,197

- AM ER MILL Filed June 5. 1928 3 Sheets-Sheet 1 3 Sheets-Sheet 2 r Q'Zmwra? w. J. ZL EMENT HAMMER MILL May 26, 1931.

Filed Ju ne 5. 1 92s Hun Ill/III May 26, 1931 w. J. CLEMENT I 1,807,197

HAMMER MILL Ifiled June 5'. 192a 3 Sheets-Sheet 3 circular paths within a casian Patented May 26, 1931 UNITED STATES PATENT OFFICE WALTER J. CLEMENT, OF UTICA, NEW YORK, ASSIG-NORlTO THE BOSSERT CORPORA- TION, F UTICA, NEW YORK, A CORIPORATION OF NEW YORK HAMMER MILL Application filed J'une 5, 1928. Serial at. 282,981.

This invention relates to grinding or disintegrating mills of that type which employ a plurality of hammers caused to rotate in g into which the material treated is introduce Mills of this type are commonly provided with exhaust fans by which the milled material is drawn out from the casing. This invention, therefore, relates to improvements in such fans and in the control and regulation of theair current-s.

Other advantageous constructions will become apparent from a more complete description ofan embodiment of the invention disclosed in the accompanying drawings in which v Figure 1 is an end elevation of a mill embodying this invention. T

Figure 2 is a detail section to a larger scale on line 22-of Figure 1. I

Figure 3 is a perspective view of a hammer. Figure 4 is a vertical section on line of Figure 1. f Figure 5 is an end elevation of the exhaust Figures 6 and 7 are detail sections on lines 6-6 and 7-7, respectively, of Figure 5.

Figure 8 is a fragmentary section through the upper portion of the mill.

Figure 9 is a section on line 9-9 of Fig-.

ure 4 but on a larger scale. Figure 10 shows in perspective a removable screen support.

Figure 11 is a view similar toa portion of Figure 9, but showing the use of spaced bars in place of a screen.

Figure 12 is a detail perspective showing the manner in which the bars of Figure 11 may be spaced.

Referring to these drawings, 1 indicates a casing generally cylindrical in form. This comprises a lower half section 2 and an upper half section 3 hinged to the section 2 along one side as at 4. By this means the upper section may be turned backwardly about the axis 4 to open the casing along a central horizontal median line. The lower section 2 comprises a pair of end walls 5 and6 which are shown as castings, the central top portion of which is provided with a semi-circular depression at 7 to receive a shaft 8ext'ending axially through the casing and shown as journaled in suitable bearings such as the ball bearings 9 which are supported on brackets 10 onthe end wall members 5 and 6.

Within the casing the shaft 8 has fixed thereto a plurality of disks 11 spaced by spacing collars 12 axially thereof, and between these disks are pivoted hammers as at 15, these hammers being shown as pivoted on bolts 16 which pass through the several disksll in spaced circular array adjacent to their peripheries. The hammers are thus arranged to swing in circular paths about the axis of the shaft 8 as this shaft is rotated, and, 'as. is usual with mills of this type, the hammers are arranged so that they are in substantial rotational and axial balance and so that they sweep through substantially the full volume of the interior of thecasing. The end wall portions 5 and 6 are shown of substantially rectangular outline, but they serve to support a lower wall portion of the casing substantially semicylindrical in outline. For this purpose each of the Walls 5 and 6 are shown as provided with arcuate grooves 20,

- the grooves of the two end wall members be- 1ng arranged in opposed relation to receive between them the wall members defining the lower half of the circular casing. These grooves may receive interchangeably a variety of such members, the particular type of members desired being controlled by the character of the material being handled by theinill. For example, in Figures 1, 9 and 10 this lower wall member is shown as comprising a perforated sheet metal plate supported on its outer face across the length of the casing by means of a skeleton support separate from the screen and shown detached in ig re 10. This skeleton support comprises a pair of side plates 30, which as shown best in Figure 9, are of suflicient length and width to extend over the top facesof the end wall members 5 or 6 and to overlie longitudinal side portions 27 and 28 which are interposed between the end plates 5 and 6 and hold them in the proper spaced relationship. Extending between the plates 30 are shown semicircular ribs 32 which may be spaced apart at intervals by means of pipe or sleeve spac-' ers 33, through which and through mating holes in the ribs 32, extend rods 34 which may be threaded at opposite ends for the reception of securing nuts 35 by which the ribs 32 and spacers 33 may be rigidly pressed together. While only one line of spacers is showmin Figure 10, it will be evident that a plurality of such spacers lengthwise of the ribs may be employed, as shown for example in Fi re 9.

The ribs 32, and the screen plate 25 supported thereby, together make up a portion of suflicient thickness to fit within the grooves 20 of the end plates 5 and 6 and they may be inserted or removed from these grooves, when the upper portion 3 of the casing is opened, above the axis 4 by moving them endwise relative to these grooves.

It will thus be seen that screen plates having any desiredarrangement or size of openings through which the properly milled material may pass may be employed, or in case it is not desired to use such a screen plate, the screen plate and its skeleton support may be replaced by other members such as a series of bars shown at 40 in Figure 11. These bars are each of a width suitable for engagement at their ends within the grooves 20 and they may be spaced as by means of blocks shown at 41 in Figure 12, each block having its side portions cut away at one end as at 42 so that when the blocks are placed in the position shown in Figure 12, adjacent cut away portions form sockets of suflicient size to receive the ends of the bars 40 therein. The blocks 41 are arcuate in form so as to fit within the arcuate grooves 20.

Around the semicircular wall formed by either screen plate 25 or the series of bars 40,

inclined roof portion 62. Along the hinged side the upper section 3 is provided with an. arcuate longitudinal wall 64 which forms substantially a continuation of the cylindrical outline of the lower casing wall. 70 When the upper section is closed this wall portion 64 rests on the other longitudinal edge portion of the lower cylindrical wall, and this, together with the wall portion 61,

holds the lower cylindrical wall section 75 against displacement longitudinally of the grooves 20. Between the inner end of the wall portion 64 and the wall portion 61 is an open space through which material to be milled may be introduced into the casing. To facilitate such introduction a chute is shown, the inner end of which extends beneath the roof portion 62 but is spaced from the inner end of the wall portion 64. This chute 65 is shown as supported by suitable bars 66, the lower ends of whichare pivoted at any suitable point to the lower section 2, herein shown as on the hinge axis 4, and the upper ends of which are adjustably fixed to one or more 9 longitudinally slotted plates 67 fixed to the under side of the chute. By adjustment of the engagement of theupper end of the bar 1 66 with the plate 67 the inclination of the chute may be adjusted as desired. The lower. forward-end of the chute is shown as fixed to a rod 70 which extends between the end plates 60 of the upper section. As shown a baflie 7 2 is hinged at 71 to the end plates 60, this baflie extending down within the chute so as to somewhat close off the opening through which material is fed into the casing and to prevent too ready passage of air into the casing through the feed opening.

It will be noted that the rod 70 is spaced 1 there is provided a chamber, the outer walls/from 'the inner edge of the wall 64. In

of which are shown as defined by longitudinally' extending plates 50 which engage the "side wall portions 51 of a trough portion 52 which extends longitudinally beneath the cas ing. This trough portion 52 may be closed oil at one end as by the plate 53 (see Figure 8) and its opposite end may be connected through a pipe 54 with a suitable exhaust mechanism, one example of which will be more fully described later.

The upper section of the casing comprises a pair of end walls 60. their back edges being substantially arcuate in form. and being connected by a cover plate 61. This cover plate at its lower end rests upon the upper edge of the lower semicylindrical wall portion, seating either on one of the plates 30 of the skeleton screen support. or on the top bar 40 where such bars are employed, and holds the lower semicylindrical wall portion in position when the upper section is closed. The arcuate portion 61 is of gradually increasing radius as it becomes further distant from the lower section 2 and finally merges in an upwardly handling some materials it is desirable to leave such a space, but inconnection with the handling of other materials, it is desirable to moreor less bridge this space. Consequently a plate 73 is shown as hinged to the rod 70,

.it being possible to adjust this plate 73 so as to bridge this opening and form a continua tion of the lower wall of the chute leading to the inner edge of the wall 64 as shown in one position by dotted lines 73a in Figure 8, or

.to ;be moved backward" and permit a free opening between the end-of the chuteand the wall 64 as shown in the'dotted line position 7 36, or to have its outer edge rest on the outer faceof the wall 64 to define an open topped pocket 7 4 across the open top of which the material must pass from the ower end of the chute to enter the casing. The plate 73 may be fixed in this pocket-forming position as by means of the locking arms 7 5, which may be brought against its rear "face or it may be held in backwardly extending open position by resting on shoulders 76 thereon where these arms are .bent about the end flanges 77 of the wall portion 64 by which this wall plates .60.

' When relatively light material such as oats isbeing handled by the mill, this plate 73, which forms a hopper door, is moved to open position so as to permit air to enter from the suction produced, as will be later described, thus to blow the light material into the hammer chamber, while any heavy foreign materials which may be in the oats, drop into the space between the chute and the wall 64 and drop past the opened plate 73 and are thus separated from the mass to'be treated in the mill.

The plate may be closed, as shown in full lines in Figure 8, when it is desired to grindshelled corn or other material which is too heavy to be swept into the casing by the air, but which also may contain relatively heavy foreign bodies. Such foreign bodies then lodge in the hopper while the corn or other material flows over its open upper face and portion is shown as fixed to the end from time to time such bodies may be cleared from the hopper by raising the plate. The plate 7 3 is placed in bridging position asby 73a when it will have no utility in its other positions, it being used in this position for example, whenbones or the inore substantial bodies are to be milled.

In order to prevent the material passing into the casing through the chute from tending to lodge in the end portions of the casing beyond the hammers, deflecting members 80 shown as curved castings of generally triangular cross section, may be fixed in the corners between the end wall and the side walls 61.

These members 86m ay have tapering ends as at 81, the outer of suchtapering ends serving to properly guide the material and the-inner tapering ends serving to clear the-hammers in; their rotation.

In order to produce the air circulation heretofore mentioned, the pipe 54 is herein shown as of gradually increasing diameter and leads to the'outer end and intake portion of a centrifugal fan shown at 85. This fan is provided with a generally cylindrical casing as at 86 of any suitable construction, within which is mounted to rotate a fan impeller or rotor 87 This impeller is shown as fixed to one end of the shaft 8, to the opposite end of which is fixed the belt pulley 90. As shown best in Figures 1, 5, 6 and 7 the fan rotor com;

prises a substantially circular inner wall' formed by a hub casting 92 fixed to the end of the shaft 8 and a circular plate 93 having a central opening to receive the hub casing fixed to the outer face of aflange portion 94 thereof. Opposite to this circular end wall is an annular end wall 95, the circular central opening 96 therethrough forming the intake to the rotor. These end walls are joined by the vanes 97 arranged in circular series about" which it may be fixed to these walls, respectively. W

In order to provide most eflicient comminuting action it has been found desirable to change thesha-pe of the hammers somewhat from the practice heretofore followed. A hammer is shown detached in Figure 3. It comprises an elongated plate bar 120 having adjacent to one end an opening 121 through which the supporting bolt passes by which it is pivotally supported between the plates 11. Adjacent to itsopposite end' this elongated flat member is widened so that at its widest portion as 122 it. is at least six times, and is preferably substantially eight times its thickness. Between the widest portion and the opening 121 it is preferably narrow so that the center of gravity of the hammer is located adjacent to the widest portion and where it will be most effective in producing lmpact-on the material being treated. Out- Wardly of the Widest portion 120 the hammer each other. It is found in practice that this divergence which produces a face inclined to the radial and toward the axis of the hammer inwardly is very desirable in practice as it tends to prevent the hammers striking glancing blows on the material vwithin the casmg. Moreover the tendency of wear of such hammers is to round ofi the end edges of the striking faces, more particularly those This at the extreme ends of the hammers. divergence of these faces provides more stock which maybe worn away before the hammers cease to function satisfactorily. It is mers rdlative to their; maximum widths at their striking faces more effectually arranges the weight of the hammer for its intended work. and that it should be at least six times as wide as thick to produce the-best results. Substantially eight times, as herein shown, has been found to 'be even better, and this gfoportion may be used without danger of 1 sufficient-lateral stability of the hammer elements due to their thinness.

From the foregoing description of an embodiment of this invention, it should be evident to those skilled in the .art that various changes and modifications might be made therein without departing from the spirit or also found that the thickening of the hamscope of this invention as defined by the appended claims. i

1. A mechanism of the class described comprising a casing, operative mechanism within said casing, a chute for delivering ma terial to be treated by said mechanism .to said casing, the adjacent end of said chute being spaced from a portionof said casing,

and an element adjustable to and from a pos1t1on bridging said space and when in brldgmg pos1t1on formlng a continuation of said chute. r

2. A mechanism of the class described comprising a caslng, operative mechanlsm comprising a casing, operating mechanism.

within saidcasing, a chute for delivering material to be treated by said mechanism to said casing, the adjacent end of said chute being spaced from a portion of said casing, and a member adjustable between a position bridging said space to conduct material from said chute directly to the interior of said casing,

and L a position defining with said casing a pocket over an open portion of which material from said chute must pass to enter said casing.

4. A mechanism of the class ,described, comprising a casing, operating mechanism within said casing, a chute for delivering material to be treated by said mechanism to said casing, the adjacent end of said chute being spaced ber adjustable between a position bridging said space to conduct material from said chute directly .to the interior of said-casing,

and a position defining with said casing a pocketover an open portion of which material from said chute must pass to enter said casing, and means for maintaining less than atmospheric pressure in said casing whereby air entering through said 'chute carries the lighter material oversaid pocket when said elment is in pocket-defining position, while the heavy material is retained in said pocket; 5. A mechanism of the class described,

comprising a generally cylindrical casing, a.

plurality of hamme rs' mounted to-rotate in said casing,-said casing having an opening through its upper portion, and a cover portion extending inan' upwardly inclined direction from one side of said opening, a chute extending toward said opening beneath-said from a portion of said casing, a memcover portion, the inner edge of said chute being spaced from the edge of said opening and a plate hinged to the inner edge of sa1 chute and adjustable to bridge said space or to engage said casing back from the edge of said opening and define with said casing a pocket between said casing and the inner end of said chute.

6. A mechanismof the class described, comprising a generally cylindrical casing, a plu-. rality of hammers mounted to rotate in said casing, said casing having an opening through its upper portion, and a cover portion extending in an upwardly inclined direction from one side of said opening, a chute extending'toward said opening beneath said cover portion, the inner edge of said chute being spaced from the edge of said opening, and a plate hinged to the inner edge of said chute and adjustable to bridge said space or to engage said casing back from the edge of said opening and define with said casing a pocket between said casing and the inner end of said chute or to provide an open space between said chute and easing.

7. A machine of the class described comprising a casing, operative mechanism with in said casing, and means for delivering material to said casing including an open topped pocket over which the material passes, said pocket having means adjustableto open or close its lower portion.

8. A machine of the class described comprising a casing, operative mechanism within said casing, and means for delivering material to the interior of said casing including an open topped pocket over which the material passes, said machine including means for maintainin less than atmospheric pressure within sai casing, and said pocket hav- 1ng,means ad ustable to open or close said lower ortion to thereby permit or stop the.

'fiow o air through said pocket to the interior of said casing. v 9. A machine ofthe class described comprising a casing, operative mechanism within 4 said casing, a chute for delivering material to be treated by said mechanism to said casing, the adjacent end of said chutebeing spaced from a portion of said casing, and means defining with said casing a pocket at said space over which material from said chute must pass to enter said casing, said defining means being adjustable to close or open said pocket.

In testimony whereof I; have afiixed my signature.

WALTER J. CLEMENT. 

